4.4 Main applications of detectors for in-situ measurements

Before selecting an instrument, it is important to understand both the activity concentration values that are to be verified, the capabilities of the monitoring instruments and the characteristics of the potentially contaminated material. Some types of instruments are quite expensive, a factor that may limits their availability for a given study.

Answering to the following questions will assist greatly in selecting the most appropriate instrument and monitoring technique:

• What is/are the radionuclide(s) of concern?


• Do they emit alpha, beta or gamma/X ray radiation?


• Which is the expected activity concentration?


• Is the material contaminated throughout or is the contamination deposited on the surface?


• Is the contamination expected to be distributed over large areas or in focalized 'hot' spots?